Comment 663 for bug 1690085

(In reply to Lars Viklund from comment #572)
> (You people should be happy you're not running FreeBSD, there I can
> reasonably reliably hang Ryzens within hours by sending ZFS snapshots :D )

Looks like they've addressed Ryzen errata issues around August 2018:

https://github.com/freebsd/freebsd/blob/75ee4f08d3acd4bf70f24b3203fa440255873973/sys/amd64/amd64/initcpu.c#L133

Also, they've made machdep.idle=hlt and machdep.idle_mwait=0 default for Ryzen processors.

I've additionally checked the registers mentioned in FresBSD's source. Latest BIOS 4406 (w/ AGESA 0070) for my ASUS A320M-K seems to apply fixes for all affected errata.

Eventhough I can't reliably reproduce the stability issues anymore, I think it's still good practice to have Boris' patch applied, since it's addresses a known erratum. I'll test the patch and check for regressions.